100w vs 55w bulbs

KJ kyle · **Posted:** Wed Apr 15, 2009 12:49 pm

i asked about this a while back but i dont think i got a sure answer.

right now Im running hella black magic driving lights, with a 55w H3 bulb. does anyone know if i can put 100w bulbs in them?

Im assuming i would have to change the relay with the bulbs... but would the wiring harness handle the extra power?

Boiler · **Posted:** Wed Apr 15, 2009 1:27 pm

Its hard to say.

Relays, fuses, and wires will all require consideration.

1) What kind of wire do you have? If it is marginal already, then you'd need to replace it. Length, # of conductors in the bundle, etc. effect how many amps a conductor can carry.

2)How many lights are you powering total and with each wire/fuse/relay?

3) How are you getting battery power to them? What size conductor?

If you told me the size / ampacity of each item carrying current between the battery and your lights and how it is done, I could say. If you are looking for a quick answer, I'd say do not do it or you risk burning down your jeep.

KJ kyle · **Posted:** Wed Apr 15, 2009 1:49 pm

well each light has a + and - running from it, to a relay, then from the relay there is a wire that goes straight to the battery, as well as 3 wires that go to the switch, the "100w" bulbs claim the actually draw is 80 watts, and it looks to be 16ga wire. also the fuse on the power wire is 15...

SNAFU · **Posted:** Thu Apr 16, 2009 5:30 pm

I used the relay my hella 700's came with, which was a 40amp and it works fine with 100w bulbs (sylvania if that matters). I ran 10 gauge wire but i think you could easily get away with 12 (mabe even 14AWG) i was just being safe.

Boiler · **Posted:** Fri Apr 17, 2009 2:58 am

Wire length, # in the bundle, where its stuffed, etc all can effect how much current a conductor should carry. Personally I don't power anything with 16 ga except for relays, switches, indicators, etc, but they should be able to carry at least 10 amps. I've seen some charts say as high as 22. With you likely having 10ft+ wires, quite a few conductors bundled, and tucked in tight spots, I wouldn't do more than 10 with 16 ga. 100 watts / 12 volts = 8.33 amps. If you have only one light per conductor pair, you should be ok. I would however change the fuse to 10 amps. 15 amps is a lot IMO with that length and bundle.

Finally, where is your fuse placed, right after the battery? I'd definitely have one there, and use at bigger conductor to the fuse.

My setup I'm working on runs a MAXI 60 amp fuse with 6GA leads at the battery, connected to 6GA welding cable to my fuse panel in the dash. From there I'm running 14 GA to my lights and I'll have another 20 or so amps free for my next toy. I'm also putting in a 2nd panel that will have a relay between it and the battery line that switches closed when the ignition circuits are on. I'll use that for accessories that would stay on otherwise.

Kugellager · **Posted:** Sat Apr 18, 2009 9:25 am

I have 4x100W H3 light bulbs in my Hella 500's and ran a separate 14 gauge wire and relay per light to my light bar. The 55Wx2 Hella 500 sets come with one 30A relay and 14 gauge wire per pair so I reasoned to use a separate wire and relay for each 100W light. I have also grounded my light bar with ground straps directly to the sheet metal of my roof. All of my accessories are powered through the two auxiliary fuse panels under my dash panel which are powered directly from the battery by dual 6 gauge wires. My setup is probably over-engineered but it makes the system less prone to failure.

Still need to get the 160 amp alternator. :roll:

You can see my lighting wiring in my 'Mods thread' in the link in my sig line. Page two of my mods has photos of my most current wiring setup.

John
];')

100w vs 55w bulbs

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